Yokogawa 2558A AC Voltage Current Standard

The Yokogawa 2558A AC Voltage Current Standard is a precision calibration instrument for validating AC measurement devices including analog wattmeters, power meters, clamp-on testers, and current transformers. It generates stable, highly accurate AC voltage and current outputs across multiple ranges with selectable fixed frequencies or variable frequency synthesis. The instrument supports both manual front-panel operation and automated test system integration via computer interfaces, making it suitable for metrology laboratories and production quality control environments.

Technical Specifications

• Range: 1.00 mV to 1200.0 V AC


• Maximum with deviation function: Up to 1440 V AC


• Six voltage ranges: 100 mV, 1 V, 10 V, 100 V, 300 V, 1000 V


• Accuracy at 50/60 Hz: ±0.04% (10% to 120% of range: ±(0.03% of setting + 0.01% of range) at 50/60 Hz and 40–400 Hz; ±(0.05% of setting + 0.01% of range) at 400 Hz)


• Accuracy at 50/60 Hz: ±400 ppm; 40–1000 Hz: ±500 ppm AC Current Output


• Range: 1.00 mA to 60.00 A AC


• Maximum with deviation function: Up to 72 A AC


• Current ranges: 100 mA, 1 A, 10 A, 50 A


• Accuracy at 50/60 Hz: ±0.05% (10% to 120% of range: ±(0.04% of setting + 0.01% of range) at 50/60 Hz and 40–400 Hz; ±(0.06% of setting + 0.01% of range) at 400 Hz)


• Accuracy at 50/60 Hz: ±500 ppm; 40–1000 Hz: ±(0.06% of range + 0.01% of setting) Frequency


• Range: 40 Hz to 1000 Hz


• Fixed frequencies: 50 Hz, 60 Hz, 400 Hz


• Variable frequency resolution: 0.001 Hz


• Frequency accuracy: ±50 ppm


• Frequency meter mode: 20–1000 Hz Stability


• AC voltage/current: ±50 ppm/h


• General stability: ±(20 ppm of range + 30 ppm of range)/h

Key Features

• Deviation function displays output deviation as percentage of full scale


• Sweep function ramps voltage, current, or frequency from 0% to 120% of set value (selectable sweep times: 8, 16, 32, or 64 seconds) for sticking tests on analog meters


• Output divider capability for linearity testing at 25%, 50%, 75%, 100% intervals


• Digital display of actual output value eliminates manual calculation


• Common current output terminals for all current ranges

Typical Applications

• Calibration of wattmeters and power meters


• Validation of clamp-on testers and current transformers


• Linearity and harmonic testing


• Meter acceptance and conformance testing

Compatibility & Integration Multiple computer interfaces enable integration into automated test equipment systems or standalone laboratory operation via front-panel controls.